Attachment for photographic developing trays



Maid! 1938. c. F. CUNNINGHAM 2,110,356

ATTACHMENT FOR PHOTOGRAPHIC DEVELOPING TRAYS Filed Aug. '7, 1937 ITZ/UC7L1 /O7i' C07 *IzeZzLus I. 6247 uzzkg/ma,

Patented Mar. 8, 1938 UNITED STATES PATENT OFFICE ATTACHMENT FOR PHOTOGRAPHIC DEVEL- OPING TRAYS 6 Claims.

This invention relates to an attachment for photographic developing trays and particularly to a device for holding a photographic film submerged in the developing liquid during the proc- 5 ess of development and while said film is being moved back and forth through said liquid.

Devices have been provided for the purpose of holding photographic films submerged during development and in certain instances these devices have had a roller embodied therein beneath which a film may be drawn back and forth in a manner and for a purpose well known in the art. The devices mentioned, however, have been constructed'in such a manner that they necessarily must be attached to the sides of the developing trays; but trays provided for this purpose are of many styles and sizes and have sides of various heights and inclinations, and where a device must necessarily be attached to the sides of a tray not all of these devices can be satisfactorily applied to the different styles of trays to occupy a desired position therein.

The primary object therefore of this invention is to provide a device having a roller embodied therein and adapted to be detachably secured to the bottom surface of a developing tray at any desired location therein and in a manner to effectively maintain a photographic film submerged in the developing liquid a predetermined distance from the bottom of the tray while said film is being moved back and forth beneath said roller.

Another object of the invention is to provide a means located adjacent to the roller whereby a strip of film may be severed from a strip of paper to which it is attached.

Still another object of the invention is to utilize suction devices in the form of vacuum cups to secure the device of the invention to a developing tray, said cups having annular flanges embodied therein which are utilized to guide the photographic film beneath the roller.

The invention consists in an attachment for photographic developing trays as set forth in the following specification and particularly as pointed out in the claims.

Referring to the drawing:

Fig. 1 is a plan view of an attachment for photographic developing trays embodying my invention, a portion only of a tray being illustrated.

Fig. 2 is a front elevation, of the device attached to a tray, a portion of one suction member and the tray being illustrated in section.

Fig. 3 is a vertical transverse section taken on the line 3--3 of Fig. 2.

Like numerals refer to like parts throughout the several views of the drawing.

In the drawing, A represents a photographic developing tray of a type well known in the art, and B is a device of this invention secured to a smooth bottom surface 5 of said tray between the side walls thereof. The device B embodies therein a pair of suction or vacuum members 6 constructed of a suitable resilient material, as for example, fiexible rubber, having cup portions 1 formed integral therewith which are concavoconvex in form and which are adapted to be attached to the smooth bottom surface 5 of the tray A by applying pressure to said members to cause said cup portions to be flattened against said smooth surface and then releasing said pressure, all in a well-known manner. The cup portion 1 of the suction members 6 has an upstanding annular flange portion 8 extending therearound adjacent to the outer edge portion thereof which serves as a guide for the photographic film in a manner hereinafter to be described.

Mounted upon each suction member 6 is an angle bracket 9 which is secured to said member by a screw Ill and thumb nut H, the screw l being anchored in the member and projecting upwardly therefrom. A portion I2 of the bracket 9 projects downwardly and is utilized as a support for the end portion of a rod l3 which is mounted at its opposite ends in the oppositely facing portions I2 of said bracket 9, and said rod constitutes a bearing for a roller M which is mounted to rotate freely thereon. The portion l2 of the bracket 9 also projects behind the annular flange 8 in a manner to flatten out and reinforce said flange at I5 adjacent to the ends of the roller l4, thereby providing reinforced guide surfaces upon the suction members 6 between which a strip of photographic film is moved back and forth through a developing liquid located within the tray A and in which the film is held submerged by the roller I l. The roller l4 also prevents the film from curling during development.

Also mounted upon the suction members 9 and conveniently positioned above the roller l4 in a position to co-operate therewith is a knife 16 having a cutting edge I! which extends parallel to the periphery of said roller at a location where a strip of sheet material, as for example, the strip of paper which is attached to the strip of photographic film, upon passing beneath the roller l4 may be presented to said cutting edge I! in a manner to be effectively severed from the film, said roller holding said strip of paper positioned to be easily contacted with said cutting edge. The knife 16 is held securely clamped to the brackets 9 by means of the thumb nuts I l.

The device B of this invention may be positioned at any desired location Within a developing tray A and effectively secured to the bottom surface thereof by pressing downwardly upon the thumb nuts I l, and after having flattened the cup portions 1 against the bottom surface 6 of said tray, finally releasing the pressure, whereupon the device will be flrrnly secured to the tray by suction created in a well-known manner. The roller I 4 of the device, secured as it is to the bottom surface of the tray, will always be located a predetermined distance from said bottom of said tray, and the amount of developing liquid required to cause the photographic film to be submerged in said liquid may be easily determined. In moving the film back and forth through the developing liquid beneath the roller M the surfaces l5 formed by flattening out the flanges 8 of the suction cups 7 act to guide said film and hold the latter beneath said roller. The knife 16 and roller M are secured to the suction members simultaneously by means of the thumb nuts II, and said knife and roller are so positioned relatively to each other that they co-operate one with the other in enabling the strip of film to be effectively severed from the strip of paper to which it is attached.

I claim:

1. A device for guiding sheet material comprising a pair of vacuum suction members adapted to cling to a smooth surface, each of said members having an upstanding guide portion provided thereon, and a roller mounted at opposite ends thereof upon said suction members between said guide portions.

2. A device for guiding sheet material comprising a pair of vacuum suction members adapted to cling to a smooth surface, each of said members having an upstanding guide portion embodied therein, a roller mounted at opposite ends thereof upon said suction members between said guide portions, and a knife also mounted upon the suction members provided with a cutting edge extending parallel to the axis of said roller.

3. The combination with a photographic developing tray of a pair of vacuum cups adapted to be secured by suction to the bottom surface of said tray, and a roller mounted upon and between said vacuum cups and adapted to hold a photographic film submerged in a liquid in said tray.

4. A device for guiding sheet material comprising a pair of vacuum suction members adapted to cling to a smooth surface, each of said members having an annular flange portion extending therearound and projecting upwardly therefrom, and a roller mounted at opposite ends thereof upon said suction members, said flange portions being adapted to guide a stripof sheet material beneath said roller.

5. A device for guiding sheet material comprising a pair of vacuum suction members adapted to cling to a smooth surface, each of said members having an annular flange portion extending therearound and projecting upwardly therefrom, a bracket fast to each of said members and engaging the flange thereof to provide a reinforced guide portion upon the suction member, and a roller mounted at opposite ends thereof upon said brackets between said guide portions, the latter being adapted to guide a strip of sheet material beneath said roller.

6. A device of the character described comprising a pair of vacuum suction members adapted to cling to a smooth surface, each of said members having an upstanding annular flange extending therearound, a bracket fast to each of said members and engaging the flange thereof to provide a reinforced guide portion upon the suction member, a roller mounted at opposite ends thereof upon said brackets between said guide portions,

the latter being adapted to guide a strip of sheet material beneath said roller, and a knife mounted upon the suction members and provided with a cutting edge extending parallel to the axis of said roller.

CORNELIUS F. CUNNINGHAM. 

